As we grow old we all hope for some way to keep, and even sharpen our wits. The media understand this and excitedly publish claims, often based on very dodgy studies, that computerised “brain training” programs, or courses of mental exercises, sold for remarkable sums of money, will restore or even improve on our former youthful abilities. This week the Centre for Longevity at Stanford University and the Max Planck institute for Human Development in Berlin jointly published a statement that strongly questions these claims. It is signed by 78 eminent researchers in mental ageing
About time too. Over the last 30 years very many of us have worked very hard indeed, for no commercial return, to find ways to improve mental abilities in old age. My own results, and those of colleagues I admire and trust, have been so disappointing that I now feel that the failures of brain training programs are, theoretically, far more interesting than the outrageous claims that some venal salespersons make for them.
For over 150 years neuroscientists have known that some mental abilities are supported by particular, often quite tiny, specialised areas of the brain. A Japanese neuroscientist, Dr Ryuta Kawashima, was not the first to notice that when we carry out particular tasks the blood supply to the particular parts of the brain that support them briefly increases. (There is now good evidence that intense practice of particular skills does result in changes in the particular parts of the brain on which they depend. Still missing is evidence that practising particular skills results in changes in the entire brain that also benefit other skills that have not been trained).
Dr Kawashima was not the first to speculate that practising mental tasks might improve both local and general brain-blood circulation and so general brain health and mental competence. He was the first to develop a hand-held “Brain Training” games console that guides purchasers through simple tasks involving mental arithmetic, memory and decision speed and scores their performance in terms of estimated “Brain Ages”. I cannot find any way in which sensible estimates of “Brain Age” can be derived from first scores on any behavioural task. For the Kawashima tasks they are calculated from performance on first attempts when middle-aged and elderly purchasers, unused to hand-held game consoles, have initial difficulties and may be distressed by estimates of their current “brain ages. Happily they may soon become elated as their inevitable improvement is translated into to a gratifyingly young brain age.
One sad snag is that old and young people improve with practice at different rates. On the simplest possible laboratory tasks it takes only a few hundred trials for most of us to become as fast as we can ever get. Even after their first scores of attempts young adults are almost as fast and accurate as they will ever become but elderly people improve markedly from a much lower initial level to a lower final peak. At any age, on any task, practice always improves performance but in old age we need more time and effort to reach lower peaks than we could once attain (1). It is encouraging for purchasers of brain-training devices to be told that their prolonged improvements are evidence that their brain ages are steadily becoming more youthful. I do not think that this is what is happening.
Boosts to elderly morale are always good and, if the tasks we learn are useful in our daily lives, even modest gains are worth the effort. It is an excellent idea to devise programmes to re-train older people, such as myself, as fast and pleasantly as possible on any particular skills that make our lives more interesting and comfortable. It would be a greater achievement to invent training programs that do not just improve our competence on a single task but also on many others that have not been practised. Very many of us have tried very hard to do this and do not think that we have yet succeeded.
An inconvenient reality is that on more difficult skills, such as languages, mathematics or chess, older people not only start from much lower baselines but improve much less, and far more slowly than the young do. Even after long practice they never reach the performance peaks that they once attained when young. The harder skills are the greater will be the differences in learning times and in peak achievements between old and young. Of course, even very modest improvements on life-enhancing skills, like languages or mental arithmetic, are immensely rewarding and useful but, alas, older people need more time and effort to achieve them.
Sales of Kawashima’s “Brain Trainer” exceeded 3 million units in a market in which sales of 1 million are exceptional. He was urged to make controlled trials to provide evidence that practice on his brain training tasks also generalised to improve performance on others. Ichiko Fuyomo (2), reviewing Kawashima’s work for the prestigious scientific journal Nature, reports that he declined to do this. Perhaps Kawashima was prudent. Other well-intentioned efforts to evaluate brain training programmes as tools to rehabilitate cognitive performance in older people have provoked surprisingly unpleasant disputes in our placid grey science.
What has become very ugly, but also very interesting is the vehemence with which those involved in marketing of these devices react to research that questions whether they are useful. Adrian Owen, with colleagues based in Cambridge and Manchester took advantage of an offer by the BBC to sponsor a web-based experiment for a TV program “Bang goes the Theory”. In 2010 they collected data from 11,430 mainly young and middle-aged people, who had trained themselves for about 3 sessions a week for 6 weeks on tasks that involved memory, planning, spatial skills and selective attention. They published their results as a paper titled “Putting Brain Training to the Test” (3) in which they reported that, of course, people of all ages became much better on all of the particular tasks that they practised. They found no evidence that these improvements extended to other, different, unpractised tasks, even when these were quite similar to those included in the original training battery. Immediately after their paper appeared the editor of “Nature” received a letter demanding its withdrawal from a distinguished North American scientist who had reported positive results with a different training program that is currently being marketed by a company for which he is scientific advisor.
In any science, disagreements between experiments are inevitable, and frequent. They are also essential for progress because differences between results always identify important differences in assumptions, in logic, in experiments or in analyses. Endless challenging of evidence is the core of the scientific method. Science advances by disagreements and is crippled by attempts to suppress results or opinions.
It is a fine ambition to discover training techniques that can quickly and painlessly make us better at particular skills. To discover “master tasks” that can also make us much better at everything else would be a far more wonderful thing and has been a very old ambition for educationalists. Until the early 20th century, School and University curricula were based on the idea that this is just what a solid education in classical Greek and Latin achieves. A recent meta-analysis of results from 23 different studies of schoolchildren considered training programs designed to bring about general and lasting improvements in Working Memory. There was no evidence for such generalisation: any improvements were restricted to specific kinds of material (4). With many of my colleagues I have been frustrated to find that ability on any particular skill is surprisingly specific and often does not generalise even to other similar situations. Part of my personal experience of this came from supervising a study by Belinda Winder who based her Manchester MSc thesis on an experiment to test the conviction of many elderly Manchester volunteers that they had preserved their everyday competence by constantly practicing cryptic crossword puzzles. Belinda compared fanatical cryptic crossword experts aged between 70 and 85 against non-experts of their own age on memory tests, intelligence tests, vocabulary tests and tests of mental speed. She found that on all of these unfamiliar tests the experts were no better than the non-experts. Tim Salthouse reports similar results (5). It seems surprisingly difficult to show that lifelong expertise on one skill necessarily generalises to improve or preserve ability in other, quite similar, skills.
I now believe that this remarkable failure of general brain training is theoretically far more important than claims, based on dubious experiments, for general, overall mind improvements. I do not (yet) despair of becoming better at regaining some old competences, such as playing chess better than I now do, or reading Russian and Latin or doing simple mental arithmetic. My personal research, and that of the colleagues I most respect and trust convinces me that I should not waste money on commercial training programs that promise to improve my performance even on other tasks that I do not practise. In my old age I am content to improve, as much as I can, on one thing at a time because I think that this is all I have ever been able to do. I also think that the reasons why this should be the case are very interesting indeed.
- Rabbitt, P.M.A. (1993). Crystal quest: A search for the maintenance of practised skills into old age. p 188-230 In Baddeley, A.D. & Weiskrantz, L., (eds) Attention, Selection Awareness and Control. A tribute to Donald Broadbent. Oxford, Clarendon Press, OUP.
- Fuyuno, (2007). Brain craze.Nature, 447 , 18-20.
- Owen, A. M., Hampshire, A., Grahn, J. A., Stenton, R., Dajani, S., Burns, A. S. et al. (2010). Putting brain training to the test.Nature,465, 775-778.
- Melby-Lervåg, M., & Hulme, C. (2013). Is working memory training effective? A meta-analytic review.Developmental Psychology, 49, 270.
- Hambrick, D. Z., Salthouse, T. A., & Meinz, E. J. (1999). Predictors of crossword puzzle proficiency and moderators of age–cognition relations. Journal of Experimental Psychology: General,128, 131-142.